Called the “invisible disease,” fibromyalgia is estimated to impact more than 10 million Americans. And yet, so much is still misunderstood about this chronic disorder. Mayo Clinic Guide to Fibromyalgia is an invaluable resource for understanding fibromyalgia and its debilitating symptoms.Those living with fibromyalgia know it is an invasive disorder, one that can cause overwhelming fatigue, joint stiffness, sleep problems, migraines, digestive problems, and troubl...